Switch mechanism



Oct. 20, 1931. o. R. DAVIES swrircn MECHANISM Filed May 19, 1927 INVENTOR David RDavies WITNESSES:

ATTIORNEY "UNITEDFSTATES Patented Oct. 20, 1931 PATENT OFFICE ELECTRIC & MANUFACTURING COMPANY, CORPORATION OF PENNSYLVANIA swrrcn MECHANISM Application filed May 19, 1827, Serial No. 192,574, and in Great Britain June 16, 1926.

My invention relates to switch mechanisms and particularly to switch mechanisms of the separable or draw-out type; Switch mechanisms of i type employ movable structures carrying circuit breakers, with or without other accessory devices, that are adapted to be separated from fixed structures in which are rovided the terminals of bus bars-rand ca les which are to be connected through the circuit breakers carried by the movable drawout portions. In such switch mechanisms,

the bus bar and cable terminals and those of the, circuit breakers and accessory devices on the draw-out portion are frequently of the plug-and-socket type, but, in switch gear intended for heavycurrents, the separable a terminals or contact members are of the in- 'terleaved knife-blade type,;and, the surfaces are carefully finished toafiord good elec 'tricalcontact over a considerableareawhen the terminals are in engagement.

'Notwithstanding the above 7 precaution, difliculties sometimes arise through overheating at: the separable contact terminals unless the surfaces are pressedtogether to such a degree as renders the draw-out opera- L tion difficult.

vide a switch mechanism of this type having a-clamping device adapted, when moved into i an operative position, to cause the blades of simultaneously and press firmly upon'the 7 interposed blades of the other set of termig a set of terminals toapproach each other nals. a I a 'It'is afurther objectof my invention to provide an interlocking device associated i with the clamping device so that, when the latter is in its operative position, separation the above specified I rotatably inounted'transversely of a row of ranged in a plurality of rows and it will be of the two portions of the switch gear is positively prevented. These and other objects that may be made apparent throughout the further description of my invention are attained by the apparatushereinafter described and illustrated in the accompanying drawings, wherein Figure 1 is aside elevational View, partly in section,'showing my invention applied to switchmechanism for a three-phase system.

Figure 2- is a front elevational view, showing the upper part ofthe fixed portion of the switch mechanism, themovable portion being omitted, and

Figure 3 is a plan view, more or lessdiagrammatic, corresponding to the upper portion of Fig. 1.

' -My invention willbe more readily understood by referring to the drawings.

Preferably, the devicecomprises a shaft the terminals vand provided with levers, toggles or'cam's corresponding to each terminal of the said row. Usually, the terminals in such bus structures may conveniently be arevident that the invention disclosed herein enables them all to be acted upon simultaneously through the intermediary of one shaft so that the blades in each terminal are firmly pressed into contact with each other when the shaft is rotated into one position, the

pressure being relieved by rotating the shaft into another position. a The fixed portion 1 of the switch mechanism is provided with bus bars 2 and cables connections 3 in the usual manner, and the movable portion is which carries a circuit breaker 5 is adapted to slide toward and away from the fixed portion 1. v As seen in Fig. 1, each of the bus-bar ter minals comprises a plurality of knife-blade contacts 6 between which other knife-blade contacts 7 ofthe corresponding terminals carried by the movable portion 4 are adapted to 5 v :be interposed. The cable terminals, which are arranged directly beneath the bus-bar terminals, similarly comprise knife blades 8 carried by the fixed portion 1, the movable portion ficar'rying corresponding knife blades mechanisms of thisikind.

The clamping device ,13- comprises atransverse shaftlfi rotatably mounted lnbearings 17 carried by the casing .1, asshown in Figs.

.2 and 3. The shaft 16 is disposed directly above the insulators 12-of-the bus .bar terminals 1a. Upon the shaft 16are secured .three similar cams .18 correspondingto the row of three terminals 14 .therebeneath, and between the-insulators 12 :andthe cams 18 is interposed a plate 19 which assists in distributing the pressure equally upon the terminals and strengthens .the structure. At each end of the shaft 16 is secured anarm21, said arms being connected, at their free ends, by a handle22. The handle,22andarms21 constitute the operating member for the clamping shaft, andbetween .t-herarmsQl is secured a cross-bar23 adaptedito engage bosses 21, on the casing of the movable portion 4 when the parts are in .the 7 position shown in the drawings as shown inlFig. .3.

It will be readily seen=that,.w.henthe switch mechanism is closed and the'arms21 are lowered into the horizontal position,'as shown, the cams 18 press downwardly upon. the'plate 19-so that the insulating blocks.10,.11;a:nd 12 and the blades 6 and 8 of all the busbars and the cable terminals areforcedtogether and tightly clamp the interleaved blades? and 9 of the'terminals of the =movable portion 4:,

- thereby affording an excellent contact bewill be noted that, when'the cam operating lever is in its horizontal or operativeposition,

the operating member embraces'thecasing of the movable portion 4 so that the 'movable portion of the switch mechanismflis locked in the closed positiomthat is to say, with-the terminals in engagement, the structures "cannot be separated from their-closed position so long as pressure is applied, by the clamping device 13, to the interleaved contact.

It is apparent from the foregoing, that the cam shaft with its associated cams may be located below the cable terminals or, with suitable modifications in the shape of the cams, maybe located between'the two rows 'ofterminals, if desired. It will further be apparent that additionalshafts with suitable scams may beprovidedto co-operate with the shaft above described, and that the latter .shafts may be mechanically connected with pur Jose. "The shaft 1'6,for example, maybe rea' ily adaptedqto operate toggles instead of ca1ns-to=apply pressure tothe terminals as above described. Many other changes, modifications, substitutions,additions and omissions "may be made without departing from 'the spirit and scope -of the appended claims.

"I claim as, myinvention 1. A switch mechanism comprising1a-stationary structure having a bus bar disposed therein, aligned sets *of' terminal membersifor thebusbar, a movable structure having disposed "thereon a circuit 'breaker, iterrninal members forengaging and co-operatingsvith the terminal membersin thestationary struc- -ture,-and positive clamp means forimaintaining thecontact memberscarried by thermovable structure "in firm contact relation :with the contact memberdisposed in :the stationary structure when'the structuresare inoperative position, said clamp meansincluding a cam andinsulatingspaoersbetween the terminals ofasetnandbetweenthe cam and a,

terminal.

:2. Aswitch imechanism comprising-a ata- *tionary-st-i:uctnre having bus bars, terminal members for the bus bars in superimposed *relation and :arranged in srows,.n'smuvable structure having disposed thereon :a circuit breaker and contact members for engaging =andco+operating with'the contact members in :the ifixed structure, eandmeanszincluding a :shaft rotatably mounted transversely. of the rowsof the terminal memberscan'dprovided with cams, oneonlyIfor each ofsaid rows for applyingpressure to the contact members whenfthe structures are in operativeposition.

3. A switch anechanism comprising-atta- .tionary structure having fixed terminals of :the inerleaved knife bladetype, a movable structure having disposed ,sthereon a circuit breaker and contact members of rthe inter- III leave knife-blade type for enga ing and cooperatin with the fixed termina and means for firm y clamping together the blades of the terminals and the corresponding contact members when they are in engagement and an interlocking device associated with the said means so that when the latter is in its operative position the structures are positively prevented from being separated.

4. A switch mechanism comprising a stationary structure having bus bars disposed therein, contact members for the bus bars, a movable structure having disposed thereon a circuit breaker and contact members for engaging and co-operating with the contact members in the stationary structure and means for firmly clamping together corresponding contact members of both structures when they are in their operative position, the said means having an interlock associated therewith for positively preventin the separation of the structures so long as t e clamping means is in its operative position.

5. A switch mechanism comprising two relatively movable structures, each structure having contact members disposed therein and adapted to engage and co-operate with the corresponding contact members of the other structure, a clamping device for the contact members having a mechanical connection for positively preventing the separation of the structure so long as the clamping device is in its operative position.

6. An electrical device having a plurality of horizontal rows of interleaved disconnectcontact members, the said contact members of different rows being disposed in aligned vertical relation, verticall aligned insulation blocks disposed between t e contact members of separate rows and a single cam for simultaneously applying pressure to the aligned insulating blocks for positively clamping the contact members in closed relation and means for preventing the release of the respective disconnect-contact members when in one position and permitting the release of the disconnect-contact members when in another position.

7. The combination with a plurality of sets of interleaved cooperating separable contact members, of compression members between the sets and forming a stack of alternately disposed contact members and compression members and means for pressing the leaves and compression members together by applying pressure at the end of the stack to prevent separation of the contact members and to obtain good conductive contact between the cooperating members of each set.

8. The combination with a plurality of sets of cooperating overlapping separable contact members of compression members between the sets and forming a stack of alternately disposed contact members and compression members and means for pressing the contact members and compression members together by applying pressure at the end of the stack to prevent separation of the contact members and to obtain ood conductive contact between the cooperating members of each set.

9. A switch mechanism comprising a stationary structure having bus bars disposed therein, terminal contact jaws for the bus bars, a movable structure having disposed thereon a circuit breaker and contact members for engaging the terminal jaws in the stationary structure and means preventing accidental withdrawal of the movable circuit breaker structure from the stationary bus structure comprising a device cooperating with the jaws for locking the contact members against separation from the jaws.

In testimony whereof, I have hereunto subscribed my name this twenty-eighth day of April, 1927.

' DAVID REGINALD DAVIES. 

